Electrical cable, especially telecommunications cable having an outer insulative jacket surrounding plural insulated conductors, is usually run outdoors suspended between utility poles high above ground level. Exposure to the outdoor elements, especially changes in temperature and/or barometric pressure, may cause negative pressures to develop inside these non-pressurized cables. This negative pressure may cause a vacuum effect which permits moisture to enter the cable core at breaks in the outer sheath. Rainwater which enters the cable in this manner follows a gravitational path and will accumulate at the lowest point of the cable span between two utility poles. Unless drained, this rainwater can cause short circuits or other problems for the conductors running through the cable. Cable vents have been developed which resist the build-up of rainwater in the cable in two ways. First, the cable vents eliminate the cable pressure inside the cable, thus, equalizing the internal cable pressure with the atmospheric pressure and reducing the likelihood of water entering the cable. Secondly, any water which does not enter the cable is drained through the cable vents.
An existing cable vent currently on the market employs a threaded nipple which is inserted into a hole placed in the jacket. While this eliminates the problems of negative pressure developing inside the cable, the vent hole placed in the cable may, itself, permit rainwater to enter the cable. Further, placing the hole on the lower surface of the cable will not always prevent water from entering the cable since the cable has a tendency to rotate due to expansion and contraction of the cable caused by temperature and other atmospheric changes.
Therefore, it is desirable to provide a cable vent which will prevent negative pressure inside cables and yet not permit rainwater to enter therein regardless of the position of the vent. Also, it is desirable to provide a cable drain for draining water already in the cable.